This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A120471 #31 Feb 26 2024 01:52:26
%S A120471 0,6,12,42,120,366,1092,3282,9840,29526,88572,265722,797160,2391486,
%T A120471 7174452,21523362,64570080,193710246,581130732,1743392202,5230176600,
%U A120471 15690529806,47071589412,141214768242,423644304720,1270932914166
%N A120471 a(n) = 6 * A015518(n).
%H A120471 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,3).
%F A120471 a(n) = 2*a(n-1)+3*a(n-2).
%F A120471 G.f.: 6*x/(1-2*x-3*x^2). - _Colin Barker_, Jan 29 2012
%t A120471 LinearRecurrence[{2,3},{0,6},30] (* _Harvey P. Dale_, Jun 09 2017 *)
%Y A120471 Cf. A015518.
%K A120471 nonn,easy,less
%O A120471 0,2
%A A120471 _Roger L. Bagula_ and _Gary W. Adamson_, Jul 04 2006
%E A120471 Edited by _N. J. A. Sloane_, Dec 04 2006